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Search filters

Search filters are pre-tested strategies that identify the higher
quality evidence from the vast amounts of literature indexed in
the major medical databases. Filters exist for most types of experimental
design, and are comprised of index terms relating to study type
and specific terms associated with the methodological description
of good experimental design.

The search filters used by SIGN are developed in-house or are
created by other research organisations and adapted to meet SIGN
information needs. SIGN's filters may provide less sensitive searches
than used by other systematic reviewers such as The Cochrane Collaboration,
but enable the retrieval of medical studies that are most likely
to match SIGN's methodological criteria.

SIGN has devised suitable strategies for running each search filter
in Ovid implementations of Medline, Embase and CINAHL along with
other more specialised databases. The following is an explanation
of some of the search devices commonly used in SIGN filters:

/

after an index term indicates that all subheadings
were selected.

*

before an index term indicates that that term
was focused - i.e. limited to records where the term was a major
MeSH/Emtree term.

"exp"

before an index term indicates that the term
was exploded.

.tw.

indicates a search for a term in title/abstract

.mp.

indicates a free text search for a term

.pt.

indicates a search for a publication type

$

at the end of a term indicates that this term
has been truncated.

?

in the middle of a term indicates the use of
a wildcard.

adj

indicates a search for two terms where they appear
adjacent to one another

The search filter used by SIGN to retrieve systematic reviews
is an adaptation of the systematic reviews filter designed by the
Health Information Research Unit of the McMaster University, Ontario.
The systematic reviews filter emphasises specificity rather than
sensitivity.

Medline

1.

Meta-Analysis as Topic/

2.

meta analy$.tw.

3.

metaanaly$.tw.

4.

Meta-Analysis/

5.

(systematic adj (review$1 or overview$1)).tw.

6.

exp Review Literature as Topic/

7.

or/1-6

8.

cochrane.ab.

9.

embase.ab.

10.

(psychlit or psyclit).ab.

11.

(psychinfo or psycinfo).ab.

12.

(cinahl or cinhal).ab.

13.

science citation index.ab.

14.

bids.ab.

15.

cancerlit.ab.

16.

or/8-15

17.

reference list$.ab.

18.

bibliograph$.ab.

19.

hand-search$.ab.

20.

relevant journals.ab.

21.

manual search$.ab.

22.

or/17-21

23.

selection criteria.ab.

24.

data extraction.ab.

25.

23 or 24

26.

Review/

27.

25 and 26

28.

Comment/

29.

Letter/

30.

Editorial/

31.

animal/

32.

human/

33.

31 not (31 and 32)

34.

or/28-30,33

35.

7 or 16 or 22 or 27

36.

35 not 34

Embase

1.

exp Meta Analysis/

2.

((meta adj analy$) or metaanalys$).tw.

3.

(systematic adj (review$1 or overview$1)).tw.

4.

or/1-3

5.

cancerlit.ab.

6.

cochrane.ab.

7.

embase.ab.

8.

(psychlit or psyclit).ab.

9.

(psychinfo or psycinfo).ab.

10.

(cinahl or cinhal).ab.

11.

science citation index.ab.

12.

bids.ab.

13.

or/5-12

14.

reference lists.ab.

15.

bibliograph$.ab.

16.

hand-search$.ab.

17.

manual search$.ab.

18.

relevant journals.ab.

19.

or/14-18

20.

data extraction.ab.

21.

selection criteria.ab.

22.

20 or 21

23.

review.pt.

24.

22 and 23

25.

letter.pt.

26.

editorial.pt.

27.

animal/

28.

human/

29.

27 not (27 and 28)

30.

or/25-26,29

31.

4 or 13 or 19 or 24

32.

31 not 30

CINAHL

1

Meta analysis/

2

Meta analys$.tw.

3

Metaanaly$.tw.

4

exp Literature review/

5

(systematic adj (review or overview)).tw.

6

Or/1-5

7

Commentary.pt.

8

Letter.pt.

9

Editorial.pt.

10

Animals/

11

Or/7-10

12

6 not 11

Randomised
Controlled Trials

The search filter used by SIGN to retrieve randomised controlled
trials has been adapted from the first two sections of strategy
designed by the Cochrane Collaboration identifying RCTs for systematic
review.

The Observational Studies search filter used by SIGN has been
developed in-house to retrieve studies most likely to meet SIGN's
methodological critieria.

Medline

1

Epidemiologic studies/

2

Exp case control studies/

3

Exp cohort studies/

4

Case control.tw.

5

(cohort adj (study or studies)).tw.

6

Cohort analy$.tw.

7

(Follow up adj (study or studies)).tw.

8

(observational adj (study or studies)).tw.

9

Longitudinal.tw.

10

Retrospective.tw.

11

Cross sectional.tw.

12

Cross-sectional studies/

13

Or/1-12

Embase

1

Clinical study/

2

Case control study

3

Family study/

4

Longitudinal study/

5

Retrospective study/

6

Prospective study/

7

Randomized controlled trials/

8

6 not 7

9

Cohort analysis/

10

(Cohort adj (study or studies)).mp.

11

(Case control adj (study or studies)).tw.

12

(follow up adj (study or studies)).tw.

13

(observational adj (study or studies)).tw.

14

(epidemiologic$ adj (study or studies)).tw.

15

(cross sectional adj (study or studies)).tw.

16

Or/1-5,8-15

CINAHL

1

Prospective studies/

2

Exp case control studies/

3

Correlational studies/

4

Nonconcurrent prospective studies/

5

Cross sectional studies/

6

(cohort adj (study or studies)).tw.

7

(observational adj (study or studies)).tw.

8

or/1-7

Diagnostic
Studies

The Diagnostic Studies search filter used by SIGN has been adapted
from the filter designed by the Health Information Research Unit
of the McMaster University, Ontario.

Medline

exp "Sensitivity and Specificity"/

sensitivity.tw.

specificity.tw.

((pre-test or pretest) adj probability).tw.

post-test probability.tw.

predictive value$.tw.

likelihood ratio$.tw.

or/1-7

Embase

exp "SENSITIVITY AND SPECIFICITY"/

sensitivity.tw.

specificity.tw.

((pre-test or pretest) adj probability).tw.

post-test probability.tw.

predictive value$.tw.

likelihood ratio$.tw.

*Diagnostic Accuracy/

or/1-8

CINHAL

exp "Sensitivity and Specificity"/

sensitivity.tw.

specificity.tw.

((pre-test or pretest) adj probability).tw.

post-test probability.tw.

predictive value$.tw.

likelihood ratio$.tw.

or/1-7

Economic
Studies

The economic studies filter used by SIGN is an adaptation of the
strategy designed by the NHS Centre for Reviews and Dissemination
at the University of York.

Medline

1

Economics/

2

"costs and cost analysis"/

3

Cost allocation/

4

Cost-benefit analysis/

5

Cost control/

6

Cost savings/

7

Cost of illness/

8

Cost sharing/

9

"deductibles and coinsurance"/

10

Medical savings accounts/

11

Health care costs/

12

Direct service costs/

13

Drug costs/

14

Employer health costs/

15

Hospital costs/

16

Health expenditures/

17

Capital expenditures/

18

Value of life/

19

Exp economics, hospital/

20

Exp economics, medical/

21

Economics, nursing/

22

Economics, pharmaceutical/

23

Exp "fees and charges"/

24

Exp budgets/

25

(low adj cost).mp.

26

(high adj cost).mp.

27

(health?care adj cost$).mp.

28

(fiscal or funding or financial
or finance).tw.

29

(cost adj estimate$).mp.

30

(cost adj variable).mp.

31

(unit adj cost$).mp.

32

(economic$ or pharmacoeconomic$
or price$ or pricing).tw.

33

Or/1-32

Embase

1

Socioeconomics/

2

Cost benefit analysis/

3

Cost effectiveness analysis/

4

Cost of illness/

5

Cost control/

6

Economic aspect/

7

Financial management/

8

Health care cost/

9

Health care financing/

10

Health economics/

11

Hospital cost/

12

(fiscal or financial or finance
or funding).tw.

13

Cost minimization analysis/

14

(cost adj estimate$).mp.

15

(cost adj variable$).mp.

16

(unit adj cost$).mp.

17

Or/1-16

CINAHL

1

Exp economics/

2

Exp "financial management"/

3

Exp "financial support"/

4

Exp "financing organized"/

5

Exp "business"/

6

Or/2-5

7

1 not 6

8

Health resource allocation.sh.

9

Health resource utilization.sh.

10

8 or 9

11

7 or 10

12

(cost or costs or economic$ or pharmacoeconomic$
or price$ or pricing$).tw.

13

11 or 12

14

Editorial.pt.

15

Letter.pt.

16

News.pt.

17

Or/14-16

18

13 not 17

19

"Animal studies"/

20

18 not 19

21

Cochrane library.so.

22

Anonymous.au.

23

20 not (21
or 22)

Patient Issues

The search strategy below is used for all patient searches conducted at SIGN. This strategy was developed by the information team at SIGN. For each guideline, we write a search strategy for the disease. This is combined with the patient stem. The search is run in Medline, Embase, Cochrane, Cinahl and Psycinfo. Relevant papers are selected from the results, and categorized into a number of themes.